1. Field of the Invention
This invention relates to a vehicular power supply apparatus including an electric generator/motor or a fuel cell. In addition, this invention relates to an engine-drive-regulation supporting apparatus.
2. Description of the Related Art
A typical automotive vehicle driven by an internal combustion engine includes a power supply apparatus in which a battery can be charged by an alternator. Generally, the rate of the power generation by the alternator is adjusted to regulate the battery voltage at a desired level.
A typical automotive vehicle with a hybrid drive includes an electric generator/motor which can be operated in either a generator mode or a motor mode. The electric generator/motor is coupled with an engine. The hybrid-drive vehicle generally includes a power supply apparatus in which a battery can be charged by the electric generator/motor. When the vehicle is decelerated, the battery is charged by the electric generator/motor so that energy can be recovered. When the vehicle is accelerated, the battery is discharged to activate the electric generator/motor to assist the vehicle acceleration. Usually, the rate of the power generation by the electric generator/motor is adjusted to control the charge state of the battery at a target. The control of the battery charge state is to optimize the charging and discharging of the battery during the recovery of vehicle-deceleration energy and during assistance to vehicle acceleration.
A battery designed to provide an appreciable portion of power to drive a vehicle tends be large in size and heavy in weight.
Japanese patent application publication number P2000-16199A discloses a power feed apparatus for a vehicle. The power feed apparatus includes a wire harness connecting a battery and loads. The wire harness has first and second conductive members. A first comparator monitors the potential at the first conductive member. The first comparator detects when the first conductive member short-circuits to a ground. A processor connected to the first comparator activates a warning lamp when the first comparator detects short circuit of the first conductive member to the ground. A second comparator monitors the potential at the second conductive member. The second comparator detects when the second conductive member short-circuits to the ground. The processor is connected with the second comparator. The processor opens a relay switch and thereby disconnects the battery from the loads when the second comparator detects short circuit of the second conductive member to the ground.